drivers/iio/accel/mxc4005.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * 3-axis accelerometer driver for MXC4005XC Memsic sensor
  *
  * Copyright (c) 2014, Intel Corporation.
  */

 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/i2c.h>
 #include <linux/iio/iio.h>
 #include <linux/mod_devicetable.h>
 #include <linux/regmap.h>
 #include <linux/iio/sysfs.h>
 #include <linux/iio/trigger.h>
 #include <linux/iio/buffer.h>
 #include <linux/iio/triggered_buffer.h>
 #include <linux/iio/trigger_consumer.h>

 #define MXC4005_DRV_NAME		"mxc4005"
 #define MXC4005_IRQ_NAME		"mxc4005_event"
 #define MXC4005_REGMAP_NAME		"mxc4005_regmap"

 #define MXC4005_REG_XOUT_UPPER		0x03
 #define MXC4005_REG_XOUT_LOWER		0x04
 #define MXC4005_REG_YOUT_UPPER		0x05
 #define MXC4005_REG_YOUT_LOWER		0x06
 #define MXC4005_REG_ZOUT_UPPER		0x07
 #define MXC4005_REG_ZOUT_LOWER		0x08

 #define MXC4005_REG_INT_MASK0		0x0A

 #define MXC4005_REG_INT_MASK1		0x0B
 #define MXC4005_REG_INT_MASK1_BIT_DRDYE	0x01

 #define MXC4005_REG_INT_CLR0		0x00

 #define MXC4005_REG_INT_CLR1		0x01
 #define MXC4005_REG_INT_CLR1_BIT_DRDYC	0x01
 #define MXC4005_REG_INT_CLR1_SW_RST	0x10

 #define MXC4005_REG_CONTROL		0x0D
 #define MXC4005_REG_CONTROL_MASK_FSR	GENMASK(6, 5)
 #define MXC4005_CONTROL_FSR_SHIFT	5

 #define MXC4005_REG_DEVICE_ID		0x0E

 /* Datasheet does not specify a reset time, this is a conservative guess */
 #define MXC4005_RESET_TIME_US		2000

 enum mxc4005_axis {
 	AXIS_X,
 	AXIS_Y,
 	AXIS_Z,
 };

 enum mxc4005_range {
 	MXC4005_RANGE_2G,
 	MXC4005_RANGE_4G,
 	MXC4005_RANGE_8G,
 };

 struct mxc4005_data {
 	struct device *dev;
 	struct mutex mutex;
 	struct regmap *regmap;
 	struct iio_trigger *dready_trig;
 	struct iio_mount_matrix orientation;
 	/* Ensure timestamp is naturally aligned */
 	struct {
 		__be16 chans[3];
 		s64 timestamp __aligned(8);
 	} scan;
 	bool trigger_enabled;
 	unsigned int control;
 	unsigned int int_mask1;
 };

 /*
  * MXC4005 can operate in the following ranges:
  * +/- 2G, 4G, 8G (the default +/-2G)
  *
  * (2 + 2) * 9.81 / (2^12 - 1) = 0.009582
  * (4 + 4) * 9.81 / (2^12 - 1) = 0.019164
  * (8 + 8) * 9.81 / (2^12 - 1) = 0.038329
  */
 static const struct {
 	u8 range;
 	int scale;
 } mxc4005_scale_table[] = {
 	{MXC4005_RANGE_2G, 9582},
 	{MXC4005_RANGE_4G, 19164},
 	{MXC4005_RANGE_8G, 38329},
 };


 static IIO_CONST_ATTR(in_accel_scale_available, "0.009582 0.019164 0.038329");

 static struct attribute *mxc4005_attributes[] = {
 	&iio_const_attr_in_accel_scale_available.dev_attr.attr,
 	NULL,
 };

 static const struct attribute_group mxc4005_attrs_group = {
 	.attrs = mxc4005_attributes,
 };

 static bool mxc4005_is_readable_reg(struct device *dev, unsigned int reg)
 {
 	switch (reg) {
 	case MXC4005_REG_XOUT_UPPER:
 	case MXC4005_REG_XOUT_LOWER:
 	case MXC4005_REG_YOUT_UPPER:
 	case MXC4005_REG_YOUT_LOWER:
 	case MXC4005_REG_ZOUT_UPPER:
 	case MXC4005_REG_ZOUT_LOWER:
 	case MXC4005_REG_DEVICE_ID:
 	case MXC4005_REG_CONTROL:
 		return true;
 	default:
 		return false;
 	}
 }

 static bool mxc4005_is_writeable_reg(struct device *dev, unsigned int reg)
 {
 	switch (reg) {
 	case MXC4005_REG_INT_CLR0:
 	case MXC4005_REG_INT_CLR1:
 	case MXC4005_REG_INT_MASK0:
 	case MXC4005_REG_INT_MASK1:
 	case MXC4005_REG_CONTROL:
 		return true;
 	default:
 		return false;
 	}
 }

 static const struct regmap_config mxc4005_regmap_config = {
 	.name = MXC4005_REGMAP_NAME,

 	.reg_bits = 8,
 	.val_bits = 8,

 	.max_register = MXC4005_REG_DEVICE_ID,

 	.readable_reg = mxc4005_is_readable_reg,
 	.writeable_reg = mxc4005_is_writeable_reg,
 };

 static int mxc4005_read_xyz(struct mxc4005_data *data)
 {
 	int ret;

 	ret = regmap_bulk_read(data->regmap, MXC4005_REG_XOUT_UPPER,
 			       data->scan.chans, sizeof(data->scan.chans));
 	if (ret < 0) {
 		dev_err(data->dev, "failed to read axes\n");
 		return ret;
 	}

 	return 0;
 }

 static int mxc4005_read_axis(struct mxc4005_data *data,
 			     unsigned int addr)
 {
 	__be16 reg;
 	int ret;

 	ret = regmap_bulk_read(data->regmap, addr, &reg, sizeof(reg));
 	if (ret < 0) {
 		dev_err(data->dev, "failed to read reg %02x\n", addr);
 		return ret;
 	}

 	return be16_to_cpu(reg);
 }

 static int mxc4005_read_scale(struct mxc4005_data *data)
 {
 	unsigned int reg;
 	int ret;
 	int i;

 	ret = regmap_read(data->regmap, MXC4005_REG_CONTROL, &reg);
 	if (ret < 0) {
 		dev_err(data->dev, "failed to read reg_control\n");
 		return ret;
 	}

 	i = reg >> MXC4005_CONTROL_FSR_SHIFT;

 	if (i < 0 || i >= ARRAY_SIZE(mxc4005_scale_table))
 		return -EINVAL;

 	return mxc4005_scale_table[i].scale;
 }

 static int mxc4005_set_scale(struct mxc4005_data *data, int val)
 {
 	unsigned int reg;
 	int i;
 	int ret;

 	for (i = 0; i < ARRAY_SIZE(mxc4005_scale_table); i++) {
 		if (mxc4005_scale_table[i].scale == val) {
 			reg = i << MXC4005_CONTROL_FSR_SHIFT;
 			ret = regmap_update_bits(data->regmap,
 						 MXC4005_REG_CONTROL,
 						 MXC4005_REG_CONTROL_MASK_FSR,
 						 reg);
 			if (ret < 0)
 				dev_err(data->dev,
 					"failed to write reg_control\n");
 			return ret;
 		}
 	}

 	return -EINVAL;
 }

 static int mxc4005_read_raw(struct iio_dev *indio_dev,
 			    struct iio_chan_spec const *chan,
 			    int *val, int *val2, long mask)
 {
 	struct mxc4005_data *data = iio_priv(indio_dev);
 	int ret;

 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
 		switch (chan->type) {
 		case IIO_ACCEL:
 			if (iio_buffer_enabled(indio_dev))
 				return -EBUSY;

 			ret = mxc4005_read_axis(data, chan->address);
 			if (ret < 0)
 				return ret;
 			*val = sign_extend32(ret >> chan->scan_type.shift,
 					     chan->scan_type.realbits - 1);
 			return IIO_VAL_INT;
 		default:
 			return -EINVAL;
 		}
 	case IIO_CHAN_INFO_SCALE:
 		ret = mxc4005_read_scale(data);
 		if (ret < 0)
 			return ret;

 		*val = 0;
 		*val2 = ret;
 		return IIO_VAL_INT_PLUS_MICRO;
 	default:
 		return -EINVAL;
 	}
 }

 static int mxc4005_write_raw(struct iio_dev *indio_dev,
 			     struct iio_chan_spec const *chan,
 			     int val, int val2, long mask)
 {
 	struct mxc4005_data *data = iio_priv(indio_dev);

 	switch (mask) {
 	case IIO_CHAN_INFO_SCALE:
 		if (val != 0)
 			return -EINVAL;

 		return mxc4005_set_scale(data, val2);
 	default:
 		return -EINVAL;
 	}
 }

 static const struct iio_mount_matrix *
 mxc4005_get_mount_matrix(const struct iio_dev *indio_dev,
 			   const struct iio_chan_spec *chan)
 {
 	struct mxc4005_data *data = iio_priv(indio_dev);

 	return &data->orientation;
 }

 static const struct iio_chan_spec_ext_info mxc4005_ext_info[] = {
 	IIO_MOUNT_MATRIX(IIO_SHARED_BY_TYPE, mxc4005_get_mount_matrix),
 	{ }
 };

 static const struct iio_info mxc4005_info = {
 	.read_raw	= mxc4005_read_raw,
 	.write_raw	= mxc4005_write_raw,
 	.attrs		= &mxc4005_attrs_group,
 };

 static const unsigned long mxc4005_scan_masks[] = {
 	BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z),
 	0
 };

 #define MXC4005_CHANNEL(_axis, _addr) {				\
 	.type = IIO_ACCEL,					\
 	.modified = 1,						\
 	.channel2 = IIO_MOD_##_axis,				\
 	.address = _addr,					\
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
 	.scan_index = AXIS_##_axis,				\
 	.scan_type = {						\
 		.sign = 's',					\
 		.realbits = 12,					\
 		.storagebits = 16,				\
 		.shift = 4,					\
 		.endianness = IIO_BE,				\
 	},							\
 	.ext_info = mxc4005_ext_info,				\
 }

 static const struct iio_chan_spec mxc4005_channels[] = {
 	MXC4005_CHANNEL(X, MXC4005_REG_XOUT_UPPER),
 	MXC4005_CHANNEL(Y, MXC4005_REG_YOUT_UPPER),
 	MXC4005_CHANNEL(Z, MXC4005_REG_ZOUT_UPPER),
 	IIO_CHAN_SOFT_TIMESTAMP(3),
 };

 static irqreturn_t mxc4005_trigger_handler(int irq, void *private)
 {
 	struct iio_poll_func *pf = private;
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct mxc4005_data *data = iio_priv(indio_dev);
 	int ret;

 	ret = mxc4005_read_xyz(data);
 	if (ret < 0)
 		goto err;

 	iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
 					   pf->timestamp);

 err:
 	iio_trigger_notify_done(indio_dev->trig);

 	return IRQ_HANDLED;
 }

 static void mxc4005_clr_intr(struct mxc4005_data *data)
 {
 	int ret;

 	/* clear interrupt */
 	ret = regmap_write(data->regmap, MXC4005_REG_INT_CLR1,
 			   MXC4005_REG_INT_CLR1_BIT_DRDYC);
 	if (ret < 0)
 		dev_err(data->dev, "failed to write to reg_int_clr1\n");
 }

 static int mxc4005_set_trigger_state(struct iio_trigger *trig,
 				     bool state)
 {
 	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
 	struct mxc4005_data *data = iio_priv(indio_dev);
 	unsigned int val;
 	int ret;

 	mutex_lock(&data->mutex);

 	val = state ? MXC4005_REG_INT_MASK1_BIT_DRDYE : 0;
 	ret = regmap_write(data->regmap, MXC4005_REG_INT_MASK1, val);
 	if (ret < 0) {
 		mutex_unlock(&data->mutex);
 		dev_err(data->dev, "failed to update reg_int_mask1");
 		return ret;
 	}

 	data->int_mask1 = val;
 	data->trigger_enabled = state;
 	mutex_unlock(&data->mutex);

 	return 0;
 }

 static void mxc4005_trigger_reen(struct iio_trigger *trig)
 {
 	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
 	struct mxc4005_data *data = iio_priv(indio_dev);

 	if (!data->dready_trig)
 		return;

 	mxc4005_clr_intr(data);
 }

 static const struct iio_trigger_ops mxc4005_trigger_ops = {
 	.set_trigger_state = mxc4005_set_trigger_state,
 	.reenable = mxc4005_trigger_reen,
 };

 static int mxc4005_chip_init(struct mxc4005_data *data)
 {
 	int ret;
 	unsigned int reg;

 	ret = regmap_read(data->regmap, MXC4005_REG_DEVICE_ID, &reg);
 	if (ret < 0) {
 		dev_err(data->dev, "failed to read chip id\n");
 		return ret;
 	}

 	dev_dbg(data->dev, "MXC4005 chip id %02x\n", reg);

 	ret = regmap_write(data->regmap, MXC4005_REG_INT_CLR1,
 			   MXC4005_REG_INT_CLR1_SW_RST);
 	if (ret < 0)
 		return dev_err_probe(data->dev, ret, "resetting chip\n");

 	fsleep(MXC4005_RESET_TIME_US);

 	ret = regmap_write(data->regmap, MXC4005_REG_INT_MASK0, 0);
 	if (ret < 0)
 		return dev_err_probe(data->dev, ret, "writing INT_MASK0\n");

 	ret = regmap_write(data->regmap, MXC4005_REG_INT_MASK1, 0);
 	if (ret < 0)
 		return dev_err_probe(data->dev, ret, "writing INT_MASK1\n");

 	return 0;
 }

 static int mxc4005_probe(struct i2c_client *client)
 {
 	struct mxc4005_data *data;
 	struct iio_dev *indio_dev;
 	struct regmap *regmap;
 	int ret;

 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 	if (!indio_dev)
 		return -ENOMEM;

 	regmap = devm_regmap_init_i2c(client, &mxc4005_regmap_config);
 	if (IS_ERR(regmap)) {
 		dev_err(&client->dev, "failed to initialize regmap\n");
 		return PTR_ERR(regmap);
 	}

 	data = iio_priv(indio_dev);
 	i2c_set_clientdata(client, indio_dev);
 	data->dev = &client->dev;
 	data->regmap = regmap;

 	ret = mxc4005_chip_init(data);
 	if (ret < 0) {
 		dev_err(&client->dev, "failed to initialize chip\n");
 		return ret;
 	}

 	mutex_init(&data->mutex);

 	if (!iio_read_acpi_mount_matrix(&client->dev, &data->orientation, "ROTM")) {
 		ret = iio_read_mount_matrix(&client->dev, &data->orientation);
 		if (ret)
 			return ret;
 	}

 	indio_dev->channels = mxc4005_channels;
 	indio_dev->num_channels = ARRAY_SIZE(mxc4005_channels);
 	indio_dev->available_scan_masks = mxc4005_scan_masks;
 	indio_dev->name = MXC4005_DRV_NAME;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->info = &mxc4005_info;

 	ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev,
 					 iio_pollfunc_store_time,
 					 mxc4005_trigger_handler,
 					 NULL);
 	if (ret < 0) {
 		dev_err(&client->dev,
 			"failed to setup iio triggered buffer\n");
 		return ret;
 	}

 	if (client->irq > 0) {
 		data->dready_trig = devm_iio_trigger_alloc(&client->dev,
 							   "%s-dev%d",
 							   indio_dev->name,
 							   iio_device_id(indio_dev));
 		if (!data->dready_trig)
 			return -ENOMEM;

 		ret = devm_request_threaded_irq(&client->dev, client->irq,
 						iio_trigger_generic_data_rdy_poll,
 						NULL,
 						IRQF_TRIGGER_FALLING |
 						IRQF_ONESHOT,
 						MXC4005_IRQ_NAME,
 						data->dready_trig);
 		if (ret) {
 			dev_err(&client->dev,
 				"failed to init threaded irq\n");
 			return ret;
 		}

 		data->dready_trig->ops = &mxc4005_trigger_ops;
 		iio_trigger_set_drvdata(data->dready_trig, indio_dev);
 		ret = devm_iio_trigger_register(&client->dev,
 						data->dready_trig);
 		if (ret) {
 			dev_err(&client->dev,
 				"failed to register trigger\n");
 			return ret;
 		}

 		indio_dev->trig = iio_trigger_get(data->dready_trig);
 	}

 	return devm_iio_device_register(&client->dev, indio_dev);
 }

 static int mxc4005_suspend(struct device *dev)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct mxc4005_data *data = iio_priv(indio_dev);
 	int ret;

 	/* Save control to restore it on resume */
 	ret = regmap_read(data->regmap, MXC4005_REG_CONTROL, &data->control);
 	if (ret < 0)
 		dev_err(data->dev, "failed to read reg_control\n");

 	return ret;
 }

 static int mxc4005_resume(struct device *dev)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct mxc4005_data *data = iio_priv(indio_dev);
 	int ret;

 	ret = regmap_write(data->regmap, MXC4005_REG_INT_CLR1,
 			   MXC4005_REG_INT_CLR1_SW_RST);
 	if (ret) {
 		dev_err(data->dev, "failed to reset chip: %d\n", ret);
 		return ret;
 	}

 	fsleep(MXC4005_RESET_TIME_US);

 	ret = regmap_write(data->regmap, MXC4005_REG_CONTROL, data->control);
 	if (ret) {
 		dev_err(data->dev, "failed to restore control register\n");
 		return ret;
 	}

 	ret = regmap_write(data->regmap, MXC4005_REG_INT_MASK0, 0);
 	if (ret) {
 		dev_err(data->dev, "failed to restore interrupt 0 mask\n");
 		return ret;
 	}

 	ret = regmap_write(data->regmap, MXC4005_REG_INT_MASK1, data->int_mask1);
 	if (ret) {
 		dev_err(data->dev, "failed to restore interrupt 1 mask\n");
 		return ret;
 	}

 	return 0;
 }

 static DEFINE_SIMPLE_DEV_PM_OPS(mxc4005_pm_ops, mxc4005_suspend, mxc4005_resume);

 static const struct acpi_device_id mxc4005_acpi_match[] = {
 	{"MXC4005",	0},
 	{"MXC6655",	0},
 	{"MDA6655",	0},
 	{ },
 };
 MODULE_DEVICE_TABLE(acpi, mxc4005_acpi_match);

 static const struct of_device_id mxc4005_of_match[] = {
 	{ .compatible = "memsic,mxc4005", },
 	{ .compatible = "memsic,mxc6655", },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, mxc4005_of_match);

 static const struct i2c_device_id mxc4005_id[] = {
 	{"mxc4005",	0},
 	{"mxc6655",	0},
 	{ },
 };
 MODULE_DEVICE_TABLE(i2c, mxc4005_id);

 static struct i2c_driver mxc4005_driver = {
 	.driver = {
 		.name = MXC4005_DRV_NAME,
 		.acpi_match_table = mxc4005_acpi_match,
 		.of_match_table = mxc4005_of_match,
 		.pm = pm_sleep_ptr(&mxc4005_pm_ops),
 	},
 	.probe		= mxc4005_probe,
 	.id_table	= mxc4005_id,
 };

 module_i2c_driver(mxc4005_driver);

 MODULE_AUTHOR("Teodora Baluta <teodora.baluta@intel.com>");
 MODULE_LICENSE("GPL v2");
 MODULE_DESCRIPTION("MXC4005 3-axis accelerometer driver");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* 3-axis accelerometer driver for MXC4005XC Memsic sensor
	*
	* Copyright (c) 2014, Intel Corporation.
	*/

	#include <linux/delay.h>
	#include <linux/module.h>
	#include <linux/i2c.h>
	#include <linux/iio/iio.h>
	#include <linux/mod_devicetable.h>
	#include <linux/regmap.h>
	#include <linux/iio/sysfs.h>
	#include <linux/iio/trigger.h>
	#include <linux/iio/buffer.h>
	#include <linux/iio/triggered_buffer.h>
	#include <linux/iio/trigger_consumer.h>

	#define MXC4005_DRV_NAME "mxc4005"
	#define MXC4005_IRQ_NAME "mxc4005_event"
	#define MXC4005_REGMAP_NAME "mxc4005_regmap"

	#define MXC4005_REG_XOUT_UPPER 0x03
	#define MXC4005_REG_XOUT_LOWER 0x04
	#define MXC4005_REG_YOUT_UPPER 0x05
	#define MXC4005_REG_YOUT_LOWER 0x06
	#define MXC4005_REG_ZOUT_UPPER 0x07
	#define MXC4005_REG_ZOUT_LOWER 0x08

	#define MXC4005_REG_INT_MASK0 0x0A

	#define MXC4005_REG_INT_MASK1 0x0B
	#define MXC4005_REG_INT_MASK1_BIT_DRDYE 0x01

	#define MXC4005_REG_INT_CLR0 0x00

	#define MXC4005_REG_INT_CLR1 0x01
	#define MXC4005_REG_INT_CLR1_BIT_DRDYC 0x01
	#define MXC4005_REG_INT_CLR1_SW_RST 0x10

	#define MXC4005_REG_CONTROL 0x0D
	#define MXC4005_REG_CONTROL_MASK_FSR GENMASK(6, 5)
	#define MXC4005_CONTROL_FSR_SHIFT 5

	#define MXC4005_REG_DEVICE_ID 0x0E

	/* Datasheet does not specify a reset time, this is a conservative guess */
	#define MXC4005_RESET_TIME_US 2000

	enum mxc4005_axis {
	AXIS_X,
	AXIS_Y,
	AXIS_Z,
	};

	enum mxc4005_range {
	MXC4005_RANGE_2G,
	MXC4005_RANGE_4G,
	MXC4005_RANGE_8G,
	};

	struct mxc4005_data {
	struct device *dev;
	struct mutex mutex;
	struct regmap *regmap;
	struct iio_trigger *dready_trig;
	struct iio_mount_matrix orientation;
	/* Ensure timestamp is naturally aligned */
	struct {
	__be16 chans[3];
	s64 timestamp __aligned(8);
	} scan;
	bool trigger_enabled;
	unsigned int control;
	unsigned int int_mask1;
	};

	/*
	* MXC4005 can operate in the following ranges:
	* +/- 2G, 4G, 8G (the default +/-2G)
	*
	* (2 + 2) * 9.81 / (2^12 - 1) = 0.009582
	* (4 + 4) * 9.81 / (2^12 - 1) = 0.019164
	* (8 + 8) * 9.81 / (2^12 - 1) = 0.038329
	*/
	static const struct {
	u8 range;
	int scale;
	} mxc4005_scale_table[] = {
	{MXC4005_RANGE_2G, 9582},
	{MXC4005_RANGE_4G, 19164},
	{MXC4005_RANGE_8G, 38329},
	};


	static IIO_CONST_ATTR(in_accel_scale_available, "0.009582 0.019164 0.038329");

	static struct attribute *mxc4005_attributes[] = {
	&iio_const_attr_in_accel_scale_available.dev_attr.attr,
	NULL,
	};

	static const struct attribute_group mxc4005_attrs_group = {
	.attrs = mxc4005_attributes,
	};

	static bool mxc4005_is_readable_reg(struct device *dev, unsigned int reg)
	{
	switch (reg) {
	case MXC4005_REG_XOUT_UPPER:
	case MXC4005_REG_XOUT_LOWER:
	case MXC4005_REG_YOUT_UPPER:
	case MXC4005_REG_YOUT_LOWER:
	case MXC4005_REG_ZOUT_UPPER:
	case MXC4005_REG_ZOUT_LOWER:
	case MXC4005_REG_DEVICE_ID:
	case MXC4005_REG_CONTROL:
	return true;
	default:
	return false;
	}
	}

	static bool mxc4005_is_writeable_reg(struct device *dev, unsigned int reg)
	{
	switch (reg) {
	case MXC4005_REG_INT_CLR0:
	case MXC4005_REG_INT_CLR1:
	case MXC4005_REG_INT_MASK0:
	case MXC4005_REG_INT_MASK1:
	case MXC4005_REG_CONTROL:
	return true;
	default:
	return false;
	}
	}

	static const struct regmap_config mxc4005_regmap_config = {
	.name = MXC4005_REGMAP_NAME,

	.reg_bits = 8,
	.val_bits = 8,

	.max_register = MXC4005_REG_DEVICE_ID,

	.readable_reg = mxc4005_is_readable_reg,
	.writeable_reg = mxc4005_is_writeable_reg,
	};

	static int mxc4005_read_xyz(struct mxc4005_data *data)
	{
	int ret;

	ret = regmap_bulk_read(data->regmap, MXC4005_REG_XOUT_UPPER,
	data->scan.chans, sizeof(data->scan.chans));
	if (ret < 0) {
	dev_err(data->dev, "failed to read axes\n");
	return ret;
	}

	return 0;
	}

	static int mxc4005_read_axis(struct mxc4005_data *data,
	unsigned int addr)
	{
	__be16 reg;
	int ret;

	ret = regmap_bulk_read(data->regmap, addr, &reg, sizeof(reg));
	if (ret < 0) {
	dev_err(data->dev, "failed to read reg %02x\n", addr);
	return ret;
	}

	return be16_to_cpu(reg);
	}

	static int mxc4005_read_scale(struct mxc4005_data *data)
	{
	unsigned int reg;
	int ret;
	int i;

	ret = regmap_read(data->regmap, MXC4005_REG_CONTROL, &reg);
	if (ret < 0) {
	dev_err(data->dev, "failed to read reg_control\n");
	return ret;
	}

	i = reg >> MXC4005_CONTROL_FSR_SHIFT;

	if (i < 0 \|\| i >= ARRAY_SIZE(mxc4005_scale_table))
	return -EINVAL;

	return mxc4005_scale_table[i].scale;
	}

	static int mxc4005_set_scale(struct mxc4005_data *data, int val)
	{
	unsigned int reg;
	int i;
	int ret;

	for (i = 0; i < ARRAY_SIZE(mxc4005_scale_table); i++) {
	if (mxc4005_scale_table[i].scale == val) {
	reg = i << MXC4005_CONTROL_FSR_SHIFT;
	ret = regmap_update_bits(data->regmap,
	MXC4005_REG_CONTROL,
	MXC4005_REG_CONTROL_MASK_FSR,
	reg);
	if (ret < 0)
	dev_err(data->dev,
	"failed to write reg_control\n");
	return ret;
	}
	}

	return -EINVAL;
	}

	static int mxc4005_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2, long mask)
	{
	struct mxc4005_data *data = iio_priv(indio_dev);
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
	switch (chan->type) {
	case IIO_ACCEL:
	if (iio_buffer_enabled(indio_dev))
	return -EBUSY;

	ret = mxc4005_read_axis(data, chan->address);
	if (ret < 0)
	return ret;
	*val = sign_extend32(ret >> chan->scan_type.shift,
	chan->scan_type.realbits - 1);
	return IIO_VAL_INT;
	default:
	return -EINVAL;
	}
	case IIO_CHAN_INFO_SCALE:
	ret = mxc4005_read_scale(data);
	if (ret < 0)
	return ret;

	*val = 0;
	*val2 = ret;
	return IIO_VAL_INT_PLUS_MICRO;
	default:
	return -EINVAL;
	}
	}

	static int mxc4005_write_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2, long mask)
	{
	struct mxc4005_data *data = iio_priv(indio_dev);

	switch (mask) {
	case IIO_CHAN_INFO_SCALE:
	if (val != 0)
	return -EINVAL;

	return mxc4005_set_scale(data, val2);
	default:
	return -EINVAL;
	}
	}

	static const struct iio_mount_matrix *
	mxc4005_get_mount_matrix(const struct iio_dev *indio_dev,
	const struct iio_chan_spec *chan)
	{
	struct mxc4005_data *data = iio_priv(indio_dev);

	return &data->orientation;
	}

	static const struct iio_chan_spec_ext_info mxc4005_ext_info[] = {
	IIO_MOUNT_MATRIX(IIO_SHARED_BY_TYPE, mxc4005_get_mount_matrix),
	{ }
	};

	static const struct iio_info mxc4005_info = {
	.read_raw = mxc4005_read_raw,
	.write_raw = mxc4005_write_raw,
	.attrs = &mxc4005_attrs_group,
	};

	static const unsigned long mxc4005_scan_masks[] = {
	BIT(AXIS_X) \| BIT(AXIS_Y) \| BIT(AXIS_Z),
	0
	};

	#define MXC4005_CHANNEL(_axis, _addr) { \
	.type = IIO_ACCEL, \
	.modified = 1, \
	.channel2 = IIO_MOD_##_axis, \
	.address = _addr, \
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
	.scan_index = AXIS_##_axis, \
	.scan_type = { \
	.sign = 's', \
	.realbits = 12, \
	.storagebits = 16, \
	.shift = 4, \
	.endianness = IIO_BE, \
	}, \
	.ext_info = mxc4005_ext_info, \
	}

	static const struct iio_chan_spec mxc4005_channels[] = {
	MXC4005_CHANNEL(X, MXC4005_REG_XOUT_UPPER),
	MXC4005_CHANNEL(Y, MXC4005_REG_YOUT_UPPER),
	MXC4005_CHANNEL(Z, MXC4005_REG_ZOUT_UPPER),
	IIO_CHAN_SOFT_TIMESTAMP(3),
	};

	static irqreturn_t mxc4005_trigger_handler(int irq, void *private)
	{
	struct iio_poll_func *pf = private;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct mxc4005_data *data = iio_priv(indio_dev);
	int ret;

	ret = mxc4005_read_xyz(data);
	if (ret < 0)
	goto err;

	iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
	pf->timestamp);

	err:
	iio_trigger_notify_done(indio_dev->trig);

	return IRQ_HANDLED;
	}

	static void mxc4005_clr_intr(struct mxc4005_data *data)
	{
	int ret;

	/* clear interrupt */
	ret = regmap_write(data->regmap, MXC4005_REG_INT_CLR1,
	MXC4005_REG_INT_CLR1_BIT_DRDYC);
	if (ret < 0)
	dev_err(data->dev, "failed to write to reg_int_clr1\n");
	}

	static int mxc4005_set_trigger_state(struct iio_trigger *trig,
	bool state)
	{
	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
	struct mxc4005_data *data = iio_priv(indio_dev);
	unsigned int val;
	int ret;

	mutex_lock(&data->mutex);

	val = state ? MXC4005_REG_INT_MASK1_BIT_DRDYE : 0;
	ret = regmap_write(data->regmap, MXC4005_REG_INT_MASK1, val);
	if (ret < 0) {
	mutex_unlock(&data->mutex);
	dev_err(data->dev, "failed to update reg_int_mask1");
	return ret;
	}

	data->int_mask1 = val;
	data->trigger_enabled = state;
	mutex_unlock(&data->mutex);

	return 0;
	}

	static void mxc4005_trigger_reen(struct iio_trigger *trig)
	{
	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
	struct mxc4005_data *data = iio_priv(indio_dev);

	if (!data->dready_trig)
	return;

	mxc4005_clr_intr(data);
	}

	static const struct iio_trigger_ops mxc4005_trigger_ops = {
	.set_trigger_state = mxc4005_set_trigger_state,
	.reenable = mxc4005_trigger_reen,
	};

	static int mxc4005_chip_init(struct mxc4005_data *data)
	{
	int ret;
	unsigned int reg;

	ret = regmap_read(data->regmap, MXC4005_REG_DEVICE_ID, &reg);
	if (ret < 0) {
	dev_err(data->dev, "failed to read chip id\n");
	return ret;
	}

	dev_dbg(data->dev, "MXC4005 chip id %02x\n", reg);

	ret = regmap_write(data->regmap, MXC4005_REG_INT_CLR1,
	MXC4005_REG_INT_CLR1_SW_RST);
	if (ret < 0)
	return dev_err_probe(data->dev, ret, "resetting chip\n");

	fsleep(MXC4005_RESET_TIME_US);

	ret = regmap_write(data->regmap, MXC4005_REG_INT_MASK0, 0);
	if (ret < 0)
	return dev_err_probe(data->dev, ret, "writing INT_MASK0\n");

	ret = regmap_write(data->regmap, MXC4005_REG_INT_MASK1, 0);
	if (ret < 0)
	return dev_err_probe(data->dev, ret, "writing INT_MASK1\n");

	return 0;
	}

	static int mxc4005_probe(struct i2c_client *client)
	{
	struct mxc4005_data *data;
	struct iio_dev *indio_dev;
	struct regmap *regmap;
	int ret;

	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
	if (!indio_dev)
	return -ENOMEM;

	regmap = devm_regmap_init_i2c(client, &mxc4005_regmap_config);
	if (IS_ERR(regmap)) {
	dev_err(&client->dev, "failed to initialize regmap\n");
	return PTR_ERR(regmap);
	}

	data = iio_priv(indio_dev);
	i2c_set_clientdata(client, indio_dev);
	data->dev = &client->dev;
	data->regmap = regmap;

	ret = mxc4005_chip_init(data);
	if (ret < 0) {
	dev_err(&client->dev, "failed to initialize chip\n");
	return ret;
	}

	mutex_init(&data->mutex);

	if (!iio_read_acpi_mount_matrix(&client->dev, &data->orientation, "ROTM")) {
	ret = iio_read_mount_matrix(&client->dev, &data->orientation);
	if (ret)
	return ret;
	}

	indio_dev->channels = mxc4005_channels;
	indio_dev->num_channels = ARRAY_SIZE(mxc4005_channels);
	indio_dev->available_scan_masks = mxc4005_scan_masks;
	indio_dev->name = MXC4005_DRV_NAME;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->info = &mxc4005_info;

	ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev,
	iio_pollfunc_store_time,
	mxc4005_trigger_handler,
	NULL);
	if (ret < 0) {
	dev_err(&client->dev,
	"failed to setup iio triggered buffer\n");
	return ret;
	}

	if (client->irq > 0) {
	data->dready_trig = devm_iio_trigger_alloc(&client->dev,
	"%s-dev%d",
	indio_dev->name,
	iio_device_id(indio_dev));
	if (!data->dready_trig)
	return -ENOMEM;

	ret = devm_request_threaded_irq(&client->dev, client->irq,
	iio_trigger_generic_data_rdy_poll,
	NULL,
	IRQF_TRIGGER_FALLING \|
	IRQF_ONESHOT,
	MXC4005_IRQ_NAME,
	data->dready_trig);
	if (ret) {
	dev_err(&client->dev,
	"failed to init threaded irq\n");
	return ret;
	}

	data->dready_trig->ops = &mxc4005_trigger_ops;
	iio_trigger_set_drvdata(data->dready_trig, indio_dev);
	ret = devm_iio_trigger_register(&client->dev,
	data->dready_trig);
	if (ret) {
	dev_err(&client->dev,
	"failed to register trigger\n");
	return ret;
	}

	indio_dev->trig = iio_trigger_get(data->dready_trig);
	}

	return devm_iio_device_register(&client->dev, indio_dev);
	}

	static int mxc4005_suspend(struct device *dev)
	{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct mxc4005_data *data = iio_priv(indio_dev);
	int ret;

	/* Save control to restore it on resume */
	ret = regmap_read(data->regmap, MXC4005_REG_CONTROL, &data->control);
	if (ret < 0)
	dev_err(data->dev, "failed to read reg_control\n");

	return ret;
	}

	static int mxc4005_resume(struct device *dev)
	{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct mxc4005_data *data = iio_priv(indio_dev);
	int ret;

	ret = regmap_write(data->regmap, MXC4005_REG_INT_CLR1,
	MXC4005_REG_INT_CLR1_SW_RST);
	if (ret) {
	dev_err(data->dev, "failed to reset chip: %d\n", ret);
	return ret;
	}

	fsleep(MXC4005_RESET_TIME_US);

	ret = regmap_write(data->regmap, MXC4005_REG_CONTROL, data->control);
	if (ret) {
	dev_err(data->dev, "failed to restore control register\n");
	return ret;
	}

	ret = regmap_write(data->regmap, MXC4005_REG_INT_MASK0, 0);
	if (ret) {
	dev_err(data->dev, "failed to restore interrupt 0 mask\n");
	return ret;
	}

	ret = regmap_write(data->regmap, MXC4005_REG_INT_MASK1, data->int_mask1);
	if (ret) {
	dev_err(data->dev, "failed to restore interrupt 1 mask\n");
	return ret;
	}

	return 0;
	}

	static DEFINE_SIMPLE_DEV_PM_OPS(mxc4005_pm_ops, mxc4005_suspend, mxc4005_resume);

	static const struct acpi_device_id mxc4005_acpi_match[] = {
	{"MXC4005", 0},
	{"MXC6655", 0},
	{"MDA6655", 0},
	{ },
	};
	MODULE_DEVICE_TABLE(acpi, mxc4005_acpi_match);

	static const struct of_device_id mxc4005_of_match[] = {
	{ .compatible = "memsic,mxc4005", },
	{ .compatible = "memsic,mxc6655", },
	{ },
	};
	MODULE_DEVICE_TABLE(of, mxc4005_of_match);

	static const struct i2c_device_id mxc4005_id[] = {
	{"mxc4005", 0},
	{"mxc6655", 0},
	{ },
	};
	MODULE_DEVICE_TABLE(i2c, mxc4005_id);

	static struct i2c_driver mxc4005_driver = {
	.driver = {
	.name = MXC4005_DRV_NAME,
	.acpi_match_table = mxc4005_acpi_match,
	.of_match_table = mxc4005_of_match,
	.pm = pm_sleep_ptr(&mxc4005_pm_ops),
	},
	.probe = mxc4005_probe,
	.id_table = mxc4005_id,
	};

	module_i2c_driver(mxc4005_driver);

	MODULE_AUTHOR("Teodora Baluta <teodora.baluta@intel.com>");
	MODULE_LICENSE("GPL v2");
	MODULE_DESCRIPTION("MXC4005 3-axis accelerometer driver");